Don't get the 970 if you are planning to play games at 4k resolution, but less than 4k it plays anything on ultra/high resolution
The SSD can be replaced with a hybrid drive "pcandparts has them" they almost are the same price as the HHD.
PCI-SIG announced the availability of the PCI Express Base 2.0 specification on 15 January 2007.[2] PCIe 2.0 doubles the bus standard's bandwidth from 2.5 Gbit/s to 5 Gbit/s, meaning a x32 connector can transfer data at up to 16 GB/s in each direction. PCIe 2.0 is still compatible with PCIe 1.1, so older cards will still be able to work in machines with this new version.
Taken from
TheGreatGrapeApe from the site
tomshardware.
PCIe 2.0 will not bottleneck any GPU but PCIe 1.0 will, so i don't recommend getting PCIe 1.0